But will school officials use any sort of barometer to measure whether the program impacts overall student grades? After all, school officials take statistics on a number of other things, including the race and ethnicity of who already participates in the free school lunch program, according to school system spokesman Joe Bass.

The answer, Bass said, is no.

“We often get asked a lot to attribute a bump in performance to one particular program, but there’s so many different programs and so many different variables that that’s really difficult to do,” Bass told Tennessee Watchdog. “While we expect to see some benefits in academics, it’s not something I think we’ll be able to track because there are so many other variables that affect academics.”

The USDA program is set for four years, and Bass said he can’t predict what will happen after that.

About 72 percent of students in the school system qualify for free and reduced lunches, and Bass said he didn’t known what kinds of household incomes the remaining 28 percent of students come from.

School system officials have an incentive to make sure as many kids as possible participate, according to Nashville’s News Channel 5.

“Metro Schools will be reimbursed based on how many free meals it serves as part of a four-year commitment,” according to the station. “The more meals served, the more likely the program can be sustained. Food costs for the district amount to about 35 percent, or more than $10 million of the school nutrition budget.”

Mark Cunningham, spokesman for the free market think tank Beacon Center of Tennessee, said that aspect of the plan troubles him.

“The district will continue to ask for more taxpayer money since it can’t possibly cut free breakfast and lunch for children, even from wealthy families, once it makes that promise,” Cunningham said.

“This is just another reason why throwing more money at education isn’t the answer. Instead of spending existing taxpayer money to give children a better education, the Nashville school district has instead decided to use the money to give free breakfast and lunch to every child, including those from upper class families.”

Bass called the move “a huge win for all of our families.”

“We have a lot of families who may fall right outside the qualifications for free- and reduced-priced lunches, but it can still be a strain on their budgets to pay three to four dollars every day for a school lunch.”

Last year the school system had a food services budget of $42 million, and $32 million of that came through USDA requirements, according to the press release.

Chris Butler is an investigative reporter for Watchdog.org who covers Tennessee and his home state of Louisiana. Chris is based in Nashville. Contact him at chris@tennesseewatchdog.org and follow him on Facebook at "Chris-Butler-WriterJournalist" or on Twitter at cdbutler1204.